The OLED is an organic thin film electroluminescent device, and it has advantages such as a simple manufacturing process, low costs, being easy to form a flexible structure and a wide viewing angle. Therefore, the technique of displaying with the OLEDs has become an important display technique.
In addition, along with the development of the display technique, the touch panel has been developed rapidly. Due to its features such as positioning in an accurate and sensitive manner, nice feel and a long service life, the capacitive touch screen has attracted more and more attention.
Currently, most of the OLED display devices that have the touch function on the market use the on-cell Touch Panel, i.e. the touch electrodes are formed at an upper surface of a packaging substrate of the OLED display panel.
However, when the touch electrode is formed on the upper surface of the packaging substrate, the packaging substrate cannot be successfully thinned so that a thickness of the OLED display panel cannot be reduced satisfactorily, which cannot meet the market requirement for thinner display panels.